Notice that the Primary Key field of "id" has duplicate values for 634! The only field that differs is the "customized_view_id". Each value in it points to the id in the _customized_views view. So if we look at that schedule on the Tableau Server we see this:

(Note: Since the "Last update" is "Never" that means the subscription is new. In the view this is denoted by (null) in the "last_sent" field)

When we open that workbook we see that the workbook has 13 sheets in it, matching the number of entries in the _subscriptions view:

In order to differentiate duplicate sheet names it may be a useful idea to have this calculation:

so you'll see this in your report:

instead of this:

Kinda shows how the lack of naming sheets can affect reports, eh?

The calculation will then allow the report to match what you'd see in Tableau Server schedules: